This program of research involves short- and long-term longitudinal studies in Goteborg (Sweden) and Berlin (Germany) of children with contrasting or distinctive child care experiences. The longitudinal study in Sweden includes 145 children recruited in 1982 at an average age of 16 months. The quality of home and alternative care had little apparent effect on the children's verbal abilities, social skills, and personal maturity as the children moved into the formal educational system and their individual personalities came to affect the adjustment to school. Longitudinal analyses revealed substantial stability over time in their personality styles, although children became less extraverted, more agreeable, more conscientious and more ego-controlled with age. Boys' levels of ego resiliency were more stable over time than girls'; boys became less resilient from middle childhood into mid adolescence, whereas girls became more ego resilient as they entered adolescence. In 2003, researchers began contacting participants to assess their status at age 20. In the Berlin longitudinal study, mothers remained in the centers with their 15-month-old toddlers during an adaptation phase and securely-attached infants had markedly lower cortisol levels than insecure infants. When the mothers stopped remaining with their infants, the cortisol responses of the securely-attached toddlers were much more dramatic than the responses of the insecurely attached toddlers. Secure toddlers also fussed/cried upon separation more than insecurely attached toddlers. Cortisol and behavioral markers of distress were correlated in securely attached but not in insecurely attached toddlers. Attachments were more likely to become or remain secure when mothers remained longer in the child care facilities with their toddlers. Comparable analyses concerned with cardiac measures of reactivity and distress are currently under way.